Hi Chao, On 09/16/2013 11:26 AM, Chao Yu wrote: > Hi Gu > >> -----Original Message----- >> From: Gu Zheng [mailto:guz.fnst@xxxxxxxxxxxxxx] >> Sent: Monday, September 16, 2013 10:09 AM >> To: Chao Yu >> Cc: Kim Jaegeuk; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx; >> linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; 谭姝 >> Subject: Re: [f2fs-dev][PATCH RESEND] f2fs: avoid allocating failure in > bio_alloc >> >> Hi Chao, >> >> On 09/13/2013 09:27 PM, Chao Yu wrote: >> >>> This patch add macro MAX_BIO_BLOCKS to limit value of npages in >>> f2fs_bio_alloc, it can avoid allocating failure in bio_alloc caused by >>> npages is larger than UIO_MAXIOV. >> >> As I know bio_alloc is based of *fs_bio_set* pool, without the limitation > of >> UIO_MAXIOV, am I missing something? > > Here is the code in bio.c, fs_bio_set is as the actual parameter pass to bs > without being inited. fs_bio_set was initiated early in the bio subsystem init. > So it may have opportunity to return NULL in this function. It may be, but may not be the thread you mentioned below. > --- > Bio.c > struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set > *bs) > { > ...... > if (!bs) { > if (nr_iovecs > UIO_MAXIOV) > return NULL; > --- > I did the abnormal test: modify the max_sectors_kb in /sys/block/sdx/queue > to 32767 for a disk with f2fs format, > and I got a segfualt in f2fs_bio_alloc after the img mounted. > Is there anyting I missed? Hmm, this change will also trigger bvec_alloc failed, did you add some traces to debug this? Regards, Gu > >> >> Thanks, >> Gu >> >>> >>> Signed-off-by: Yu Chao <chao2.yu@xxxxxxxxxxx> >>> --- >>> fs/f2fs/segment.c | 4 +++- >>> fs/f2fs/segment.h | 3 +++ >>> 2 files changed, 6 insertions(+), 1 deletion(-) >>> >>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index >>> 09af9c7..bd79bbe 100644 >>> --- a/fs/f2fs/segment.c >>> +++ b/fs/f2fs/segment.c >>> @@ -657,6 +657,7 @@ static void submit_write_page(struct f2fs_sb_info >>> *sbi, struct page *page, >>> block_t blk_addr, enum page_type >> type) >>> { >>> struct block_device *bdev = sbi->sb->s_bdev; >>> + int bio_blocks; >>> >>> verify_block_addr(sbi, blk_addr); >>> >>> @@ -676,7 +677,8 @@ retry: >>> goto retry; >>> } >>> >>> - sbi->bio[type] = f2fs_bio_alloc(bdev, > max_hw_blocks(sbi)); >>> + bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi)); >>> + sbi->bio[type] = f2fs_bio_alloc(bdev, bio_blocks); >>> sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi, >>> blk_addr); >>> sbi->bio[type]->bi_private = priv; >>> /* >>> diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index >>> bdd10ea..6352af1 100644 >>> --- a/fs/f2fs/segment.h >>> +++ b/fs/f2fs/segment.h >>> @@ -9,6 +9,7 @@ >>> * published by the Free Software Foundation. >>> */ >>> #include <linux/blkdev.h> >>> +#include <linux/uio.h> >>> >>> /* constant macro */ >>> #define NULL_SEGNO ((unsigned int)(~0)) >>> @@ -90,6 +91,8 @@ >>> (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) >>> #define SECTOR_TO_BLOCK(sbi, sectors) >> \ >>> (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) >>> +#define MAX_BIO_BLOCKS(max_hw_blocks) >> \ >>> + (min((int)max_hw_blocks, UIO_MAXIOV)) >>> >>> /* during checkpoint, bio_private is used to synchronize the last bio >>> */ struct bio_private { >>> --- >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe >>> linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> Please read the FAQ at http://www.tux.org/lkml/ >>> > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
